It is known to produce an upright vacuum cleaner with controls for controlling the operation of the motor-fan assembly, the height of the suction nozzle in relation to the floor surface, and for turning the rotary agitator on and off. There are many such cleaners having various manual or electronic controls or a combination thereof for controlling these features individually or in conjunction with one another as a system according to pre-determined settings.
In recent years, it has been found to be advantageous to produce a floor care appliance with one or more modes wherein one of the modes will be used for cleaning bare floors. In bare floor mode, it is desirous to either manually or automatically lower the suction nozzle of the vacuum cleaner to the lowest position in relation to the floor surface while simultaneously disconnecting the rotary power to the rotary agitator. Disconnecting the rotary agitator prevents the rotating agitator from damaging the floor surface. It has also been found to be desirous to vary the height of the suction nozzle according to the type of floor surface being cleaned by utilizing a rotary control dial or member having either discrete settings or variable positions. In this manner, a suction nozzle height setting may be selected according to the type floor surface or type of carpet to be cleaned. Heretofore, it is unknown to have a floor care appliance utilizing a rotary control member to control the height of the suction nozzle and to control the rotary agitator according a pre-determined position of the rotary control member
In the present invention, a rotary mode control member electronically controls a suction nozzle height adjustment motor. The suction nozzle height adjustment motor has a cam portion which adjusts the height of the suction nozzle by urging against a lever arm on the wheel carriage supporting the suction nozzle on the floor surface. A projection extending from the cam portion is operatively linked to an idler arm having a belt tensioner for tensioning and de-tensioning the agitator drive belt according to a pre-determined height of the suction nozzle. Thus, the rotary control member can be moved to a position to lower the suction nozzle closest to the floor surface and turn off the rotary agitator ortho other positions where the suction nozzle is moved to a pre-determined height above the floor surface and the drive belt is tensioned so that rotary power is provided to the rotary agitator. Therefore, the present invention fulfills a need not heretofore addressed in the prior art.